The World Flora Online

SELECTED REFERENCES

Godfrey, R. K. and J. W. Wooten. 1979. Aquatic and Wetland Plants of the Southeastern United States. Monocotyledons. Athens, Ga. Hartog, C. den. 1970. The Sea-grasses of the World. Amsterdam. Haynes, R. R. and L. B. Holm-Nielsen. 1985. A generic treatment of the Alismatidae in the Neotropics. Acta Amazon. 15(suppl.): 153--193. Johnson, E. A. and S. L. Williams. 1982. Sexual reproduction in seagrasses: Reports for five Caribbean species with details for Halodule wrightii Aschers., and Syringodium filiforme Kutz. Caribbean J. Sci. Math. 18: 61--70.

Herbs, perennial, rhizomatous, caulescent; turions absent. Leaves submersed, alternate or nearly opposite, sessile; sheath persisting longer than blade, leaving circular scar when shed, not ligulate, auriculate, lobes not scarious; blade linear; intravaginal squamules scales, more than 2. Inflorescences axillary or terminal, solitary or cymes, without spathe, sessile or pedunculate; peduncle, when present, not elongating following fertilization, not spiraling. Flowers uniasexual, staminate and pistillate on separate plants; subtending bracts absent; perianth absent. Staminate flowers: stamens 2, in 1 series; anthers adaxially connate, dehiscing vertically; pollen linear. Pistillate flowers: pistils 2, distinct, not stipitate; ovules pendulous, orthotropous. Fruits achenelike or drupaceous. Seeds 1; embryo straight.

Herbes marines, pérennes, dioïques, glabres ; rhizomes rampants. Squamules intravaginales présentes à l’aisselle des feuilles. Feuilles alternes, distiques ou spiralées, à partie basale engainante, munie de 2 auricules et une ligule apicale ; limbe linéaire, aplati ou cylindrique, avec plusieurs nervures parallèles entre lesquelles on distingue des points et stries tanninifères. Inflorescences terminales, cymeuses ou à fleurs solitaires, sessiles ou pédonculées. Fleurs sessiles ou courtement pédicellées ; périanthe absent ; Fleurs mâles à 2 anthères 4-loculaires, les thèques partiellement connées, à déhiscence longitudinale. Fleurs femelles à 2 ovaires libres, à 1 ovule pendant, portant chacune un style simple ou divisé en 2 ou 3 stigmates filiformes. Fruits : noix indéhiscentes, à 1 graine. Graines exalbuminées.

Famille des eaux maritimes tropicales, subtropicales et parfois méditerranéennes, avec cinq genres et 16 espèces, dont une au Gabon.

Leaves distichous or spiral; leaf-sheath amplexicaul, with 2 apical auricles, ligulate; blade linear with several parallel nerves, in between which tannin dots and dashes are visible Marine plants, perennial, dioecious, glabrous; rhizome creeping; vessel elements absent Fruit an indehiscent nutlet; seed 1; endosperm absent Pistillate flowers of 2 free ovaries; ovule 1, pendulous Staminate flowers consisting of 2 anthers, these 4-locular, partially connate, dehiscing by extrorse slits; pollen thread-like, without exine Flowers terminal and solitary on a short branch, or in cymose inflorescences, sessile or stalked, small, water-pollinated; tepals absent Marine plants, perennial, dioecious, glabrous; rhizome creeping; vessel elements absent Fruit an indehiscent nutlet; seed 1; endosperm absent Pistillate flowers of 2 free ovaries; ovule 1, pendulous Staminate flowers consisting of 2 anthers, these 4-locular, partially connate, dehiscing by extrorse slits; pollen thread-like, without exine Flowers terminal and solitary on a short branch, or in cymose inflorescences, sessile or stalked, small, water-pollinated; tepals absent

Plants submerged in salt water. Rhizomes creeping, usually slender. Stems shortened. Leaves sessile, alternate, subopposite, or crowded at nodes, linear, with conspicuous midvein, sheathing at base. Plants dioecious. Flowers minute, unisexual, solitary or in cymes. Male flowers pedunculate; perianth of 3 small scales or absent; stamens 1-3; anthers connate, sessile, longitudinally dehiscent; pollen grains threadlike. Female flowers sessile; perianth absent or cupular or of 3 segments; carpels 2, free; style simple or divided into 2(-4) filiform stigmas; ovule 1, pendulous. Fruitlet achene- or nutlike. Seeds without endosperm.